Burning in hi-pass capacitors

[bkeane1259]

Re: Burning in hi-pass capacitors

Songs for testing and why-

I know these songs really well and so does my ex-DJ partner who will be part of the DBT tests next week. Just thought I'd throw them out with a short explanation of what we think makes them test-worthy.


Enya (A Day Without Rain) – Heavy bass line, strings, background clave, vocal stereo imaging.
Donnie Iris (Ah! Leah!) – rockin lead and rhythm guitar, accompanying synth, tight drums and stereo vocals.
Dave Matthews Band (So Much To Say)– Acoustic guitar strings – Percussion and horns.
Mumford and Sons (The Cave) – Acoustic guitar and Vocals – banjo strings and heavy bass line.
Robert Plant (In the Mood) – Intro Hi-hat and heavy bass line with synth in the background plus main and backup vocals. Focus on guitar solo with following percussion and synth.
Dire Straits (Money For Nothing) – Intro vocals and percussion, with lead in guitar. Accompanying bass line (rather deep) and subtle background synth.
Pink Floyd (Pigs) – Sweet guitar lead in with background synth and then a very pronounced bass line with accompanying guitar and various percussion. Piano and synthesizer with that continuing lead guitar riff and a nice cow bell (with echo)….gonna be a good one.
Van Halen (Runnin’ With The Devil) – Explosive intro – lead guitar steals it. This is all about heavy metal guitar. However the lead vocals are awesome as well.
Styx (Borrowed Time) – Synth, bass, guitar intro – which leads into a heavy metal guitar + heavy drums. Good imaging with the strings and vocals. Good percussion – focus on hi-hat and drums towards end.
Hollies (Long Cool Woman) – Strings intro (the guitar is classic) – Reverb on vocals and guitar. Pterry simple recording but focus on the strings and the stereo reverb.
Toto (Rosanna) – Total focus on snare rolls, tambourine, horns and rhythm guitar initially. There’s a good synth + guitar solo and then good vocal harmony and then piano. For me, the snare rolls are the focus towards the beginning of the song.
Dire Straits (Brothers In Arms) – Intro guitar…fade into vocals, but lead guitar is the focus. Rim shots on the snare, tambourine, and classic keyboards.

[dlsbobby]

Re: Burning in hi-pass capacitors

.....Now I'm hooked on crossover mods, and I want to invest in a woodshop so I can start cranking out DIY speakers. What have I done??[/QUOTE]


Ahh yes, we have another one. Welcome to the club. This hobby is addictive. Robert.

[Herman Trivilino]

Re: Burning in hi-pass capacitors

Sadly I do not have them - I chucked 'em a few months ago. I did measure the other NPE that is in the XO (in the woofer shunt position) - It's rated 9.1uF and measured 9.7uF. The tweeter NPE cap was the same crappy brand.

Then you'll never know why that change in capacitor made the difference you heard. It could be due to burn in, but it could also be due to a relatively huge difference in capacitance. ( I say huge because this discussion has involved adding bypass caps on the order of 0.2 µF, wheras that original cap may have differed from the replaced cap by as much as 0.4 µF or more.)

[bkeane1259]

Re: Burning in hi-pass capacitors

Then you'll never know why that change in capacitor made the difference you heard. It could be due to burn in, but it could also be due to a relatively huge difference in capacitance. ( I say huge because this discussion has involved adding bypass caps on the order of 0.2 µF, wheras that original cap may have differed from the replaced cap by as much as 0.4 µF or more.)

I wish I still had the original tweeter caps, but I don't and I'm not gonna obsess about it. Here's the story in a nutshell and why I'm even bothering doing this burn-in test:

1. Bought Polk Monitor-40's for my workstation for $100 on ebay from Polk Direct. I like them...think they are a great value at that price point.
2. Read about inferior crossovers in low end Polk speakers, so I took a look at the ones in mine and sure enough, they were pretty crappy.
3. Figured I'd replace the tweeter cap with something really good (Jantzens) to see if it made a difference - it did. The difference was obvious and immediate. Larger sound stage and more dynamic vocals but not as bright or silky as the original (the original NPE with bypass was very bright but a bit harsh). HOWEVER, about 30 hours later, I started to notice a difference which seemed to evolve between 30-60 hours of use. High-end silkiness came back, but the harshness of the original cap is gone. Things like string plucks, hi-hats, cymbals, and snares seemed to be more present. This got me wanting to rebuild the WHOLE crossover with better components to see what sort of difference it would yield.
4. Read a lot about different caps on several DIY sites, etc., and thought it would be fun to buy a few extras to swap in and out of an external crossover just for fun.
5. Got mixed up in debates about the "burn-in" factor, the placebo effect, etc. So I decided to do a test of my new caps to see if burn-in is actually audible. Best way to do it is via DBT as suggested by many here, and so it goes.

I DO think my cheapo Polks sound better with the Jantzen caps but really that doesn't matter as the test I'm going to do is focused on whether one can tell the difference between a burned in cap and a brand spanking new one of the exact same rating and manufacturer.

After that "burn-in" test, I might do more tests across the different cap brands and document it, but it wasn't my original reason for starting this thread.

[Herman Trivilino]

Re: Burning in hi-pass capacitors

I wish I still had the original tweeter caps, but I don't and I'm not gonna obsess about it.

But look at what you have learned from it. Just yesterday you were convinced that you had about 8.2 µF because the OEM caps were stamped 8.0 µF and 0.22 µF. Now you know better.

I agree that there's no sense in obsessing about it, but neither should you let it bias your judgement.

2. Read about inferior crossovers in low end Polk speakers, so I took a look at the ones in mine and sure enough, they were pretty crappy.

You judge them crappy, but what's that based upon? The fact that when you replaced them there was an improvement? But that improvement could be due to only a change in the capacitance. I'm not saying you were wrong or you were right. You very well could be right. I'm just saying that you're reaching a conclusion and that you owe it to yourself to consider the evidence you're using to reach that conclusion. Don't obsess about it, but just consider it.

3. Figured I'd replace the tweeter cap with something really good (Jantzens) to see if it made a difference - it did.

Again, with the judgement. Jantzens are "really good". What's that based on? The higher price? Other people's opinions? The improvement you heard (which may be due to a change in capacitance).

Look, I don't have the answers. But I have learned two things. One, that we humans have to be careful about drawing conclusions from our observations. The history of science is full of examples of seemingly obvious, yet entirely wrong, conclusions being drawn from evidence. I can't stress this enough. There are lots of examples of consensus among experts and everyone else, sometimes lasting for decades or even centuries, that were later shown to be entirely wrong.

The other is that I,being human, have to refer to experts. There are a lot of them out there and they sometimes agree on something (which doesn't necessarily mean they're right) and they sometimes don't.

There is no consensus among the experts that expensive caps make a difference in the way a speaker sounds. Some say it does, but many say it doesn't.

I get your point. You want to test only for a burn-in effect. That's great, but please don't, along the way, assume that more expensive caps sound better. If you want to reach that conclusion, you owe it to yourself to make sure you've done it based on conclusions drawn from observations, not assumptions

[bkeane1259]

Re: Burning in hi-pass capacitors

I get your point. You want to test only for a burn-in effect. That's great, but please don't, along the way, assume that more expensive caps sound better. If you want to reach that conclusion, you owe it to yourself to make sure you've done it based on conclusions drawn from observations, not assumptions

I hear you loud and clear. For me, it's not a question of $$$ -- it doesn't bias my judgement. After all, I'm working with budget speakers to begin with that I think sound great despite their low price point. I AM trying to make them sound better because I think Polk skimped on the XO's. However, I'd be happy as a pig in $hit if the Dayton caps end up sounding the best when all is said and done. I will gladly leave them in the permanent XO's. I fully understand that synergies come into play with crossovers and speaker components. No worries there. I will be approaching this whole test with a very open mind, and will happily document the results - starting next weekend. :D

I appreciate your feedback....I'm learning a lot along the way. This is a great forum.

[r-carpenter]

Re: Burning in hi-pass capacitors

I am going throw something in here.
A friend of mine works in the lab and has an access to $$$$$$ test equipment.
Sure enough he is an audiophile or I should say he likes Hi fidelity sound reproduction. He run a multitude of tests on different capacitors. Dissipation factors, tangent angle... don't ask, he is a PHD in physics and I don't care enough to ask either. So, he found that Jansen is actually a worst performing capacitor among the bunch and most similar to NPE cap. Now, having said that, none of tests show differences in the usable range for loudspeaker crossovers. :D

[bkeane1259]

Re: Burning in hi-pass capacitors

don't ask, he is a PHD in physics and I don't care enough to ask either. So, he found that Jansen is actually a worst performing capacitor among the bunch and most similar to NPE cap.

Umm, Jensen maybe? Or are you saying Jantzen? Both have pretty good reputations for quality capacitors. I have read that the Jantzen crosscaps are not very good. I am extremely happy with the Jantzen Superior Z line.

Everyone has an opinion. As we continue to discuss this, it really makes me curious to see what happens with the tests. Wish I had more time on my hands to get things rolling right away, but for sure we will get rocking on this next weekend.

[r-carpenter]

Re: Burning in hi-pass capacitors

yep these guys http://www.parts-express.com/mfg/jan...cfm#capacitors
I misspelled.
Opinions are just that... opinions.

[Wolf]

Re: Burning in hi-pass capacitors

Which model, Roman? It does make a difference.

I know what I hear!!

Later,
Wolf

[r-carpenter]

Re: Burning in hi-pass capacitors

Which model, Roman? It does make a difference.

I know what I hear!!

Later,
Wolf

Yeah, don't we all:rolleyes: hear the difference.
Sorry man, just had to rub it in.

Anyhow, can't remember if he was testing Z-Standard or Crosscap capacitors.
Compared them to Mundorf, and some other stuff. I had too little interest in this aspect to ask, at the time. I can ask again if he kept the data.

[Face]

Re: Burning in hi-pass capacitors

I've always said cross caps are awful.

Roman, you should have him test those MR's.

[LSV8]

Re: Burning in hi-pass capacitors

I've always said cross caps are awful.

I purchased 14 CrossCaps for a recent 7 channel build. 7 of one value, 7 of another. Of the 14, two measured more than 10% out of spec, and one was DOA! So apparently these are batch tested rather than individually tested before shipping out. I've never had a DOA cap before...

[Paul K.]

Re: Burning in hi-pass capacitors

I don't know what the standard QC procedures are for passive electronic components, but I suspect SPC is used with its attendant sampling inspection plans rather than 100% testing of all parameters on all production. Appropriate SPC will ensure "most" of the time that "most" of the items produced will be good and meet specs. If 100% of the items have to be tested for 100% of their parameters to ensure acceptable quality, something's wrong with materials and/or processes.
Paul

I purchased 14 CrossCaps for a recent 7 channel build. 7 of one value, 7 of another. Of the 14, two measured more than 10% out of spec, and one was DOA! So apparently these are batch tested rather than individually tested before shipping out. I've never had a DOA cap before...

[LSV8]

Re: Burning in hi-pass capacitors

I don't know what the standard QC procedures are for passive electronic components, but I suspect SPC is used with its attendant sampling inspection plans rather than 100% testing of all parameters on all production. Appropriate SPC will ensure "most" of the time that "most" of the items produced will be good and meet specs. If 100% of the items have to be tested for 100% of their parameters to ensure acceptable quality, something's wrong with materials and/or processes.
Paul

I absolutely agree. Though statistical process analysis wasn't my favorite ME course... I understand the application. haha.

What I meant by that statement is although we might get the feeling of "hand made", attention to detail, quality goodness in boutique caps... they are no different from any other mass produced electrical component.

I sure hope "dead" is WELL under the LCL! :D